I don't care what the new job is, but I think new job focus should be on Damage over Time usage and/or Chain/channeling usage.

I play all FFXIV jobs and have developed a personal feel or see "flavors" to all jobs. I'm not saying they are all unique, but each stands out and mix up gameplay. Tanks eat damage and spill into defense or offense, magic vs physical, etc. DPS are melee vs magic, range vs close, etc. Healers shield vs regen, damage vs cards, etc.

I've also played since the start of FFXIV, I went through the hate of Version 1, then ARR saved the gamed. I also went through the game becoming "easier" by eliminating the ADVANCED play styles with stance changing and ability combo usages.

Summoner was the closet jobs that had a focus on Damage over time spell usage. Not sure why they "got rid of it" other than the focus was on the summons or maybe the math calculations became a headache.

I can envison a job that "stacks DoT" and must maintain a channeling effect, think Astrolgian "shield" move or that guy in castle with chainsaw/machine gun move, or eos heal channeling.

Imagine "cast a spell" for an AoE DoT, then combo with level 2 spell to increase damage and a final level 3 combo that has DoT going from 10 damage > 20 damage > 30 damage. Or a Channeling move that increase damage ever tick until channeling complete, but players cannot move think Meditation.

Heres some job example. Geomancer, Aoe Waterga then combo with Icega creating hailstrom, final combo is Thunderga forming Maelstrom. Or channeling, Light spells or dark spells for increasing damage. Channeling timers could be adjust depending on how strong you wanted the effect of spells to be.

How about Corsair? Aoe Gasbomb toss for poison damage over time, then combo it with Oil toss for "slow and damage effect" finish it with Flame toss for to create Firestorm"
Channeling move could be? Something with Light or dark elemental. "lazer shot" "ebony
flame"?